+---------------+ | Microcontroller | +---------------+ | | v +---------------+ | Paddle Interface | +---------------+ | | v +---------------+ | Speed and Tone | | Controls | +---------------+ | | v +---------------+ | Memory and Storage| +---------------+ | | v +---------------+ | Output Stage | +---------------+
The paddle inputs (DIT and DAH) are the most fundamental part of any keyer schematic. Typically, a is used: the tip connects to the DIT paddle, the ring to the DAH paddle, and the sleeve to ground. Pull‑up resistors are not strictly necessary because the firmware can activate the microcontroller’s internal pull‑ups, but many schematic examples include external 10 kΩ resistors to ensure clean signals. Small capacitors (e.g., 10 nF) are also often placed across the paddle inputs to filter out contact bounce.
Modern K3NG schematics use . This requires only 4 wires:
Support for displays (LCD/OLED) and user-defined function buttons The Core K3NG Keyer Schematic Explained k3ng keyer schematic
If you wish to reverse the paddle wiring (e.g., for left‑handed operation), the software provides a command (“N” in command mode) that swaps the DIT and DAH assignments without changing any hardware.
One of the more advanced options is connecting a . The schematic for a PS/2 keyboard is straightforward: two pins (clock and data) with 4.7 kΩ pull‑up resistors to +5 V. USB keyboards are usually connected through a USB‑to‑serial adapter, which appears to the Arduino as a serial device. Likewise, a matrix keypad (3×4 or 4×4) can be wired directly to eight or more Arduino pins. The schematic for the keypad is simply the standard row‑column matrix connection.
If you want, I can for a specific configuration (e.g., Nano + optoisolator keying + I2C LCD + speed pot). Just tell me which features you need. Small capacitors (e
31 Jul 2023 — For this example this is pin 12. - for the schematic provided as an example : # define tx_key_line_1 12 // (high = key down/tx on) Google Groups CW Keyer - kk9jef
Highly recommended because they only require 4 wires. Connect VCC to 5V, GND to Ground.
"I added three," Elias said, pointing to three tactile switches. "One for 'CQ', one for my call sign, and one for '5NN TU'." One of the more advanced options is connecting a
The Dit and Dash lines connect to individual digital I/O pins (commonly D2 and D5, though customizable in the code). The paddle's common ground connects to the Arduino GND.
By building the K3NG keyer, you gain an incredibly robust piece of shack equipment that rivals keyers costing hundreds of dollars, while building valuable electronics fabrication skills.
Here is a basic outline of the schematic:
Open keyer_features_and_options.h and uncomment the lines corresponding to the hardware you plan to install. For example, to add a rotary encoder, uncomment #define FEATURE_ROTARY_ENCODER . For a basic keyer without an LCD, you may leave most options commented.
